This transgene expresses Cre recombinase under the control of a mouse glycoprotein hormone alpha-subunit (Cga) gene. This promoter is active in the pituitary primordium beginning at embryonic day 9.5. Cre recombinase expression is detected in the anterior and intermediate lobes of the pituitary gland, in cardiac, and in skeletal muscle. Low to no level of expression is detected in the posterior pituitary, lungs, kidneys, brain, adrenal glands, and gonads.